Centrifuge



A. KRUPP Jan. 19, 1932.

CENTRIFUGE 1926 2 Sheets-Sheet Filed Feb. 12

Jan. 19, 1932,

A. KRUPP CEN Filed Feb. 12 19 TRIFUGE 2 Sheets-Sheet 2 Patented Jan. 19, 1932 UNITED STATES- PATENT OFFICE ANTON KRUPP, OF MILWAIIKEE, WISCONSIN, AS SIGNOR, BY MESNE ASSIGNMENTS, T0 UNITED STATES HOFFMAN MACHINERY CORIORATION, OF NEW YORK, N. Y.,

A CORPORATION OF DELAWARE CENTRIFUGE Application filed February 12, 1926. Serial No. 87,859.

This invention relates to centrifugal machines, and more particularly to centrifugal driers, such as are used in laundrics and other cleaning establishments.

In such a centrifugal machine a rotating or spinning member is mounted usually on a vertical shaft within a suitable housing. The rotating element carries a basket or container in which the articles to be dried are deposited so that when the element is spun at a high speed, the moisture will be thrown out by centrifugal force. The container is usually perforated so that this moisture may pass through the walls thereof to be thrown off and deposited on the walls of the housing.

The opening in the casing provided for access to the rotating element is usually pro vided with a protecting cover or guard so as to prevent any one coming in contact with the rotating element while in motion.

As such machines are often installed in places where a number of persons are working and sometimes where a single operator must handle several machines, it is desirable to provide means for locking such a guard in place so that it cannot be opened or removed so long as the machine is in motion. It is also desirable to provide arrangements to prevent the starting of such a machine before the guard is in place.

One of the objects of this invention. therefore, is to provide a safety device of novel design which will not only secure the guard in place, but will operate to lock the same against release so long as the machine is moving.

Another object is to provide means to prevent starting of the rotating element before the guard has been put in protecting position.

Further objects will appear from the following description taken in connection with the accompanying drawings. in which:

Figure 1 is a view, partly in elevation and partly in section, showing a centrifugal ma chine embodying this invention;

Figure 2 is an enlarged detail of the arrangements for locking the guard in place;

Figure 3 is a plan view of Figure 2;

Figure 4 is an enlarged detail showing the mechanism for locking the guard against release while the machine is in motion;

Figure 5 is a partial section on line 5+5, Figure 4; and

Figure 6 is a detail similar to Figure 2, showing another embodiment of this invention.

In the embodiment illustrated, 1 designates the casing or housing of a centrifuge having a rotating element 2 mounted therewithin on a vertical shaft 3. The shaft 3 is carried in a bearing 4 flexibly mounted by means of elastic washers 5 on a central bear ing support 6 mounted on the base 7 of the centrifuge. These elements may be of any suitable construction well known to those skilled in the art.

The rotating element carries a pulley 8 which is driven by a belt 9 from a driving pulley 10 which in turn is driven through gearing 11 from a. shaft 12 to which is fixed a driving pulley 13 and which carries a loose pulley 14. A belt shifter 15 sliding on a guide 16 is connected by a link 17 to an arm 18 mounted on a rod 19 carrying an arm 20 connected by a link 21 to an operating lever 22. also be of any suitable type well known in the art.

The opening in the top of the housing 1 is closed by a guard or cover 23 usually constructed of a heavy wire mesh or similar material. This cover is mounted by means of a pair of short arms 24 on a shaft 25 mounted in bearings 26 on a bracket 27, which in turn is mounted on the housing 1. The shaft 25 carries a circular sector 28 which is recessed as shown at 29 so as to receive the edge of another sector 30. As seen from Figure 2, the arrangement is such that when the sector 30 engages the recess 29, rotation of the sector 28 and the shaft 25 will be prevented by the interlocking of these sectors and accordingly the guard 23 will be locked in place. The sector 30 is notched as shown at 31 so that when said sector 30 is rotated in a clock- Wise direction, as scen in Figure 2, until the notch 31 comes opposite the sector 28, the latter sector may enter said notch and permit the guard to be opened. The sector 30 This driving arrangement may Gil I the driving belt on the shaft is provided with a second notch 32 adapted to receive a projection 33 carried by the hub 34 of the operating handle 22. The projection 33 enters the notch 32 when the operating handle is moved to such a position as to shift to the fixed pulley 13. The driving belt 35 then connects the machine with a suitable source of power not shown. With the projection 33 thus engaged in the notch 32, the interlocking sectors 28 and 30 are secured in such a position as to prevent the opening of the guard. Therefore, this guard is locked in protecting position so long as the machine is running. When the belt shifting handle 22 is swung to such a position as to shift the belt 35 to the loose pulley 14, the projection 33 will pass out of the notch 32 and free the interlocking sectors 28 and 30 for manipulation so as to release the guard.

The sector 30 is provided with a hub 36 which is fixed to a shaft 37 mounted in bearings 38 on the bracket 27. Pivoted in a slot 37 so as to be rockable thereon is a handle 40. This handle 40 extends through an off-set slot 41in an arcuate plate 42 mounted on one of the bearings 38 so as to be concentric with the shaft 37 The slot 41 retards the movement of the handle 40 so as to separate such movement into two steps since it is necessary to move the hair dle through half of its full are. then rock the same along the shaft 37 and along the off-set in the slot 41 before the second part of the movement can be accomplished. The purpose of this will be more fully set forth hereinafter. The hub 36 carries an arm 43 connected with a rod 44 extending downwardly and connected at its lower end to the locking mechanism illustrated more particularly in Figures 4 and 5.

The rod 44 connects at its lower end with a lever 45 pivoted on the brake-shaft 46 of the machine and having an arm 47 as illustrated in Figure 4.

The bearing support 6 is recessed with a vertical channel 48 communicating at its upper end with an inclined transverse channel 49. Slidably mounted in the channel 48 is a pair of plungers 50 and 51. These plungers are connected by a pin 52 fixed to the plunger 51, but sliding in a slot 53 in the plunger 50. The pin 52 engages the lower end of a spring 54 mounted in the slot 53 and bearing against the upper terminal thereof as illustrated in Figure 4. The arm 47 is provided with a forked end adapted to receive the pin 52, the arm being inserted between the plungers 50 and 51. Movement of the arm 47 will, therefore, operate to raise or lower these plungers.

The upper ends of the plungers 50 and 51 extend into a frame or enclosure 55 mounted in the channel 49 and at the same inclination. Mounted within the frame 55 is a steel ball 56. This ball is just large enough to engage the sides of the rame 55 but to move free y therewithin. As seen from Figure 5 the inclined position of the frame 55 will cause the ball 56 to roll downwardly to the right hand end thereof, Figure 5, so as to be itioned over the end of the plunger 50; T li end of this plunger is tapered, inclining outwardly as shown in Figure 4, so that when this plunger is raise the ball 56 will be forced radially outwardly in the frame 55. The pulley 8 overhangs the bearing support 6 so that its inner surface will be positioned in I front of the open frame 55 so as to prevent the ball 56 from being ejected therefrom. However, when the ball is forced outwardly by raising the plunger 50, it will come in contact with the pulley 8. If this pulley is rotating at the time the ball will be caused to roll in the direction of rotation, that is upwardly in the frame 55 to a position over the end of the plunger 51. When in this position the ball will block the movement of the plunger 51. This plunger has its end beveled in a rearward direction as shown in Figure 4 so that when it is raised to engage the ball 56, the support 6 and, therefore, disengage it from the pulley 8. When the plungers are again lowered. the ball being released will roll downwardly in the inclined frame 55 to its normal position as shown in Figure 5.

The Operation of this device is as follows: When the machine is at rest, the belt shifting mechanism is in such a position that the projection 33 is free of the sector 30 so that the latter is free to move. The operator may now move the handle 40 so as to rotate the shaft 37 in order to turn the sector 30 to such av position that the sector 28 may enter the notch 31, releasing the guard so that it may be opened for the insertion or removal of the work from the machine. As the handle 40 is moved to the right, Figure 3, the arm 43 is depressed and the rod 44 is moved downwardly. This causes the lever 45 to pivot on the shaft 46 so as to raise the arm 47. This tends to raise the plungers 50 and 51. The plunger 50, however, is blocked by the ball 56. The spring 54, however, permits the arm 47 and the plunger 51 to rise. There is nothing, therefore, to prevent the movement of the handle 40 through its complete are so that the sector 30 may be turned so as to release the guard.

When the guard is raised the sector 28 enters the notch 31. thereby locking the sector 30 in such a position as to prevent movement of the arm 22 by its interlocking engagement with the projection 33.

If with the machine running of its own momentum following the disconnection of the driving mechanism the operator were to attempt to release the guard by moving the handle 40, he would be constrained to move said it will hold said ball back against lit) handle in two steps by the action of the slot 41. As soon as the first step of such movement has been carried out, the arm 43' will be rotated by such movement so as to depress the rod 44 and raise the plunger-s 50 and 51. Thus raising the plunger 50 will throw the ball 56 out against the pulley 8. The rotation of this pulley operates to rollthe ball as previously described to a posit-ion over the plunger 51. l n this position the ball blocks the movement of this plunger and, therefore, prevents the carrying out of the second movement of the arm 40. The operator will, therefore, be prevented from rotating the sector 30 far enough to release the guard. It will be noted that the machine must be brought to a complete stop before the guard can be released.

A spring 39, connecting the lever 45 with the housing 1, tends to raise said lever and the rod 44. This spring, therefore, puts the shaft 37 and the sector 30 under tension tending to rotate them to locking position. \Vhen the guard is lowered to its protecting position, therefore, the handle 40 will snap back in the slot 41 to its mid-way position. In this position the guard is not yet secured in protecting position, but the ball 56 is still held by the plunger 50 in engagement with the pulley 8, so that the machine cannot be started. The operator must move the handle 40 to its fully retracted position in order to release the ball 56. As soon as the handle reaches such position the sector 30 will snap into the notch 29 under the action of the spring 39, and the guard will be locked in place and the starting handle released.

Figure 6 shows the application of this looking mechanism to an electrically driven machine. In this embodiment the notch 31 in the sector 30 is adapted to receive a roller 58 on the end of an arm 59 constructed and arranged so as to operate in any suitable manner a switch 60 to clos'e either directly or through a relay the circuit of the starting motor when the sectors are in a position as shown in Figure 2. When said sectors are moved to a position to release the guard, the roller 58 will be forced out of the notch 31 and the arm 59 depressed so as to open the motor circuit.

It will be seen, therefore, that this invention provides a simple and effective device for rendering the operation of such a centrifugal machine fool-proof. The action of the ball 56 depends entirely on the movement of the pulley 8. The ball is frictionally engaged with such pulley and is moved by such frictional engagement. The movement rolls the ball to its locking position and in the latter position the ball is again thrown out of engagement with the pulley. It will be seen, therefore, that there is practically no strain put on the locking parts due to their engagement with the moving element. The simple rolling engagement makes the movement easy and free of shocks or strains and practically without wear on the operating parts. The simple connections from this locking mechanism to the interlocking sectors 28 and 30 makes it possible to provide a rugged construction and one which will not easily get out of repair. The arrangement for providing two movements of the arm 40 insures against the possibility of executing this movement too quickly so that the ball 56 may not have sufficient time to operate. Only an instant retardation in the movement of the arm 40 is suflicient to insure reliable action of the ball. This arm must be brought to its fully retracted position in order to release the machine for starting. The device may be applied by simple changes to either belt driven or electrically driven machines and in either case renders the same secure against wrong manipulation. Since the locking device is operated directly by the rotating element, it is independent of the driving power or gearing. Consequently, the slipping off of a belt or the failure of power or the like will not effect its efficiency as a protective device.

It is obvious that various changes may be made in details of construction without departing from the spirit of this invention; it is, therefore, to be understood that this invention is not to be limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

1. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element, a safety device, comprising, a friction member adapted for movement by a frictional engagement with said driven member, an inclined guide for said member, and connections from said friction member to said guard adapted to prevent release of the guard while said element is in motion.

2. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element, a safety device, comprising, a rotatable member adapted for movement by rolling engagement with said driven member, an inclined guide for said rotatable member, and connections from said rotatable member to said guard adapted to prevent release of the guard while said element is in motion.

3. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element, a safety device, comprising, a ball adapted for movement by engagement with said member, and connections from said ball to the guard adapted to preventrelease of the guard while said element is in motion.

4. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element,

a safety device, for movement by en gement with said member, an inclined gui e for said ball, and connections from said ball to the guard adapted to prevent release of the guard while said element is in motion.

5. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element, a safety device, comprising, a ball adapted for engagement wit sai member to be moved thereby, an actuator for releasing the guard, means cooperating with said actuator to cause en agement of said ball with said element, sai ball being ada ted upon movement to revent operation 0 said actuator to release t e guard.

6. In a machine of the character described having a rotatable element provided with a driven member; and a guard for said element, a safety device, comprising, a ball adapted for engagement with said member to be moved thereby, an actuator for releasing the guard, a locking element adapted for cooperation with said ball when moved to prevent operation of said actuator to release the guard, and a resilient member adapted upon movement of said actuator to cause engagement of said ball with said driven member.

7. In a safety device, of the character described, the combination with a rotatable member, of a stationary member having a recess inclined upwardly in the direction of rotation of said rotatable member, a ball in said recess, a plunger movable into said recess and adapted to move said ball into contact with said rotatable member, a second plunger movable into said recess, and means for moving said plungers into said recess, said means being resiliently connected with the first mentioned plunger and positively connected with the second mentioned plunger.

In testimony whereof I afiix my signature this 20th day of January, 1926.

ANTON KRUPP.

comprising, a ball adapted 

